Melanin blocks UV at the epidermis to protect skin organs beneath the dermis and scavenges free radicals to protect the skin. Also, melanin is the primary determinant of skin color and thus is the cause of pigmentation such as stains, freckles and dark spots when existing in excess.
Melanin is produced on melanocytes, which are found in the basal layer of the epidermis. It is known that the production of melanin is promoted by stimuli such as UV or inflammation. Accordingly, the melanin production can be inhibited by decreasing external stimulation, blocking signal transduction, or inhibiting synthesis or activity of tyrosinase, which is a melanin-producing enzyme.
Until now, kojic acid, hydroquinone, arbutin, azelaic acid, aloesin, 4-butylresorcinol, resveratrol, ceramide, sphingosine-1-phosphate, sphingosylphosphorylcholline, and the like are known to be able to regulate melanin production by promoting tyrosinase decomposition or regulating glycosylation. However, these substances are not widely used due to unsatisfactory skin whitening effect and stability as well as skin irritation. Accordingly, it is necessary to develop a substance having excellent skin whitening effect with low side effects.